The following U.S. patents comprise the closest known prior art: U.S. Pat. Nos. 2,625,070, 2,900,862, 3,155,760, 3,319,502, 3,320,844, 3,443,470, 3,527,134, 3,546,995, 3,761,598, 3,789,722.
The extensive listing of prior art indicates that there are known in the prior art many musical instrument keyboards which are adapted to be played in pedal fashion by the foot. Generally speaking, these keyboards are arranged with the keys defining the same scale patterns as a standard piano keyboard; i.e., the familiar 12 note repetitive pattern in side-by-side relationship. Although this arrangement is consonant with the accepted note layout, it does not provide convenient foot access to the notes most often played in a bass accompaniment. For example, the third, fifth, seventh, and octave intervals frequently used in bass accompaniment to piano or guitar require substantial lateral excursions of the foot, thereby increasing the time required to play these notes and the fatigue to the foot and leg. More importantly, these long lateral excursions may often result in poor placement of the foot and errors in the accompaniment. It is quite clear that the foot does not have the sensitivity nor the aptitude of the hand for striking the proper key.
One example of a prior art attempt to overcome this shortcoming is found in U.S. Pat. No. 3,546,995, cited above. This device provides two rows of keys arrayed in lateral opposition with respect to a medial pivot shaft. The keys may be played with the heel and toe, thus placing more keys within easy reach of the foot without long lateral excursions. In this device all keys are arrayed in a common linear or curved plane, with no tactile differences available to the musician to indicate differing keys. Also, each pair of opposed keys are actually a common bar pivotally joined to a medial pivot bar in seesaw fashion, rendering playing of these keys in rapid succession more difficult. Furthermore, the note arrangement ascribed to the keys is not convenient for playing bass accompaniment lines.